Screw holding attachment for screwdrivers



March 1956 R- E. GEARHART ET AL 2,737,988

SCREW HOLDING ATTACHMENT FOR SCREWDRIVERS Filed March 26, 1952 2Sheets-Sheet l a 2a 2 6 ""II 3 12 2; llllfilln 20 Z i Z .7479. J 23 J36INVENTORQ A701 5 Q/fiarf BY/Pwe/f 5 6480:

March 13, 1956 R. E. GEARHART EI'AL 2,737,938

SCREW HOLDING ATTACHMENT FOR SCREWDRIVERS Filed March 26. 1952 2Sheets-S heet 2 IN V EN TOR. Roy Gear/Eff /Poker f? I'CAEHJ UnitedStates Patent SCREW HOLDING ATTACHMENT FOR SCREWDRIVERS Roy E. Gearhart,Kansas City, Mo., and Robert F. Dickens, Overland Park, Kans.

Application March 26, 1952, Serial No. 278,702

4 Claims. (Cl. 14550) This invention relates to new and usefulimprovements in screw holders, and has particular reference to a screwholding device adapted to serve as an attachment for an ordinary screwdriver.

Various types of screw holding devices have been made which involvegenerally a split or divided bit adapted to be inserted in the screwdriver slot of a screw, and having some means for spreading the parts ofsaid bit to engage the sides of said screw driver slot to hold the screwfirmly as it is started in or removed from the object in which it isthreaded. Said bit is customarily mounted at the end of a long shank,for providing access to screws which cannot be conveniently reached byhand. Also, various attempts have been made to strengthen screw holdersof this type so that they can deliver the considerable torque necessaryto set a screw tightly, or to loosen a screw which has been previouslyset. So far as is known, these attempts have been largely unsuccessful,due to the fact that splitting or dividing the tip of the bit renderssaid bit relatively fragile, and entirely too weak to deliver thenecessary torque. Consequently, the usual result has been that two toolsare necessary, a screw holder for starting the screw, and a screw driverfor setting it tightly. This is obviously inconvenient, and expensive.

The principal object of this invention is, therefore, the provision of ascrew holding device which may be quickly and easily attached to anyordinary screw driver, and which is operable by its relationship to saidscrew driver to hold a screw, and which at the same time will notinterfere with the use of the screw driver in performing its usualfunctions.

Another object is the provision of a screw holding attachment which maybe used in connection with the standard screw driver having awedge-shaped bit, or with a screw driver having a bit which is cruciformin crosssection, the latter being commonly known as a Phillips screwdriver, and wherein the bit of the screw holding attachment itself isadapted, with or without modification, to engage the cruciform slot of aPhillips screw.

A further object is the provision of a screw holding device of thecharacter described having a bit specially adapted to hold screws havingworn screw driver slots.

Other objects are simplicity and economy of structure, dependability andefficiency of operation, adaptability for use with many types and sizesof screwdrivers and with screws having screwdriver slots of varyingwidths, and adaptability to deliver a considerable turning torque to thescrew held thereby.

With these objects in view, as well as other objects which will appearin the course of the specification, reference will be had to thedrawing, wherein:

Fig. 1 is a side elevational view of a screw driver of ordinary design,showing a screw holding attachment embodying the present inventionmounted in operative position thereon.

Fig. 2 is an enlarged fragmentary view similar to Fig. 1, showing thescrew holding attachment retracted to its inoperative position.

Fig. 3 is a view similar to Fig. 2, but showing the screw holder inoperative engagement with a screw.

Fig. 4 is a fragmentary view taken at right angles to the line of sightin Fig. 3, with parts broken away.

Fig. 5 is a sectional view taken on line V-V of Fig. 3.

Fig. 6 is a lower end view of the screw holding device as shown in Fig.1, with parts omitted.

Fig. 7 is an enlarged sectional view taken on line VIIVII of Fig. 3.

Fig. 8 is a view similar to Fig. 4, showing a modification of the shapeof the screw holding bits.

Fig. 9 is a fragmentary view similar to Fig. 3, showing a secondmodification of the shape of the screw holding bits.

Fig. 10 is an enlarged sectional view taken on line X--X of Fig. 9. v

Fig. 11 is an enlarged fragmentary view similar to Fig. 1, showing athird modification of the shape of the screw holdingbits, thismodification being particularly adapted for use in Phillips-type screws.

Fig. 12 is a view similar to Fig. 11, showing the screw holdingattachment mounted on a Phillips-type screw driver and in engagementwith a Phillips-type screw.

Fig. 13 is an enlarged section taken on line XII-X[I of Fig. 12.

Fig. 14 is an enlarged section taken on line XIV-XIV of Fig. 12.

Like reference numerals apply to similar parts throughout the severalviews, and the numeral 2 refers to a screw driver of ordinary designincluding a rod-like shank 4 to one end of which is rigidly attached ahandle 6, and the opposite end of which is formed to present awedge-shaped bit 8, the relatively inclined faces 10 and 12 of whichconverge toward the free end thereof.

The screw holding attachment forming the subject of this invention isdesignated generally by the numeral 14, and is preferably formed of asingle unitary piece of fiat spring stock, out and formed as shown. Atits upper end it is formed to present a generally tubular clip 16 openlongitudinally along one edge to form a C-shaped crosssection, as shownin Fig. 7, whereupon said clip may be snapped over the shank 4 of thescrew driver. Said clip is thereby mounted for frictional slidingmovement along said shank. Extending longitudinally from said clip are apair. of flat resilient arms 18 and 20 disposed respectively ondiametrically opposite sides of shank 4. As shown in Fig. 1, said armsnormally extend beyond the end of bit 8, and are curved inwardly towardeach other at their free ends as indicated at 22, and are then rebent sothat their extreme end portions extend substantially longitudinally ofthe device to form bits 24 and 26 respectively.

As best shown in Fig. 6, the end portions of arms 18 and 20 areoppositely notched as at 28 so that hits 24 and 26 each have a widthequal to substantially half the width of said arms, and so that saidbits may move substantially into a common plane coinciding with thecentral plane of screw driver bit 8. Thus said bits, in conjunction,form a single split bit parallel to and substantially coextensive withbit 8. As best shown in Fig. 3, bits 24 and 26 are inclined downwardlyand slightly outwardly in opposite directions, for a purpose which willbe more fully described hereinafter.

Carried by each of arms 18 and 20 adjacent the free end thereof are apair of ears 36, disposed respectively at the opposite lateral edges ofsaid arm and being turned inwardly to bear slidably at their inner endsagainst the adjacent wedge face 10 or 12 of screw driver bit 8. Theseears thus serve as fulcrums in the operation of the screw holding bits24 and 26, as will be more fully described. The bit contacting edgesurfaces of ears 30 are arcuately curved, as shown.

The operation of the device as shown in Figs. 1 to 7 is, substantiallyas follows: When it is desired to engage a screw, clip 16 is movedmanually along shank 4 until arms 18 and 20 extend beyond the end ofscrew driver bit,- as shown in Fig. 1. The normal or unfiexed form ofsaid arms is such as'to hold bits24=and26 in alignment as. shown in Fig.6. The bits are then insertedin the usual manner in the screwdriver slot32 of a screw 34, and the screw driver is pushed axially through clip16, thereby introducing the: wedge-shaped screw driver bit 8 between thefulcrum members 30 of the respective'arms 18 and 20. The" wedge faces:10 and 12 of said bit flex arms 18 and 20 outwardly, moving the bits 24and 26 transversely outwardly in opposite directions to engage theopposite side walls of screw slot 32, thereby holding the'screw firmlyin position on the bits 24 and 26. The parts then have the relativeposition shown in Fig. 3. The wedge taper of bit 8 is sufficientlyslight that the system" is self-locking. Thatis, fulcrum members 30 willnot be moved along the bit 8 by the longitudinal component of their own:force thereagainst- As'isplainly seen in Fig. 3, the-opposite outwardinclinations of bits-24 and 26 provide that-they grip the screwprincipally at the bottomofscrew slot 32. This isimportant in that ittends to provide a'secure grip on screws the slots of which have becomeworn through continued-use. The distance to which hits 24 and 26 must'beexpanded depends of-course on'the width of the screw slot 32, and istherefore subject to considerable variation. Consequently, bits 24' and26 may contact the side walls of the slot 32 while the lower edge of bit8is still asubstantial distance away from contact with arms 18 and 20 atthe upper ends of bits'24 and 26. This contacting relationship is shownin Fig. 3, and functions as a means for providing a definite stopfor'bit 8, and prevents damage to the relatively fragile bits 24 and 26which might otherwise occur due to' excessive transverse loading of saidbits if screwdriver bit 8 were advanced too far between'members 30. If,as described above, bits24'-and 26 are moved into actual grippingcontact with the screw slot'wallsbefore the end of bit 8 contacts arms18 and 20, then continued movement of bit:8 will merely cause arms 18and 20 to bow slightly outwardly as shown in Fig. 3, permitting'bit 8 tomove on to its stop point without unduly overloading bits 24 and 26. Theopposite inclination of bits 24'and 26'is also useful in thisconnection. The bowing action'of arms 18 and 20 as just described wouldcause the bits totilt relatively inwardly, with a resultant tendency ofthe screw to slip 01f, were said bits not initially inclined outwardly.

Since the screw is then held firmly as in Fig. 3, it may be started inany'screw hole which is accessible by use 'of thefull length of shank 4,which may of coursebe of any desired length. Furthermore, since thescrew holding bits are operable by a simple pressure at the rearward endof handle 6, the toolis equally useful in removing screws frominaccessible screw holes.

When it is desired to apply the final torque for setting a screwtightly, or for initially loosening a tightly 'set screw, clip 16 issimply moved upwardly on screwdriver shank 4 until bits 24 and 26 areretracted above the end of bit 8, as shown in Fig. 2. Bit 8 is thusexposed for use in its usual manner, without the necessity of removingthe screw holding attachment from the screw 'driver.

While the present device is not adapted to deliver the heavy torquesnecessary in setting some screws tightly, and while within applicantsknowledge no split-bit screw holder has ever been produced which ispractical for this purpose, the present device nevertheless possessesstructural features which make the tool exceptionally sturdy andadapted, within inherent-limitations, to 'deliver a maximum torque. Forexample, the formation of the bit in two longitudinally split sectionspermits the use of spring stock of a thickness virtually as' largei'asthewidth of the screw slot,"and consequently ofgre'ater strength.Furthermore, the positioning of fulcrummembers 30 at the extreme lateraledges of arms 18 and 20 provides that screw driver bit 8 can deliver amaximum torque to said arms through said fulcrum members.

It is believed quite apparent that the form of our in vention so fardescribed is adapted also for use in the cross-shaped slot of certainscrews commonly known as Phillips screws, the bits 24 and 26 merelybeing in serted in one of the arms of said slot and operated in theusual manner. However, as shown in Fig. 8, the screw slot 36 of aPhillips s'erew'38 iscustomarily taperingly reduced toward its bottom,and this necessarily limits the insertion of bits 24' and 26 therein.Fig. 8 illustrates a slight modification of the bits which increasestheir usefulness as applied to Phillips screws. Therein, the screwholding bits 40 and 42, which cor respond to bits 24 and 26 of thespecies shown in Figs. 1 to 7, have their outer or distal cornersbevelled as indicated at 44, to a degree corresponding to the taper ofscrew'slot 36. This permits the bits to be inserted into the slot to agreater extent. The operation and structurethereof is otherwiseidentical with that of Figs. 1 to 7.

Figs. 9 and l0'illustrate a further modification of the hits as appliedto standard screws. Therein the two' bits 46 and 48 do not'ov'erlap eachother or move into' coplanar relation. Instead, each has a full width ofthe corresponding arms 18and'20, and they normally bear flat againsteach other except when expanded by bit Sas shown. The bits mustnecessarily be somewhat thinner, inorder that both maybe insertedsimultaneously in groove 32 of the screws, and this is provided bynotching the outer facesofsaid bits asindicated at'50. The faces of saidnotchesare inclined downwardly'and outwardly, in order that the bitswill grip the screw at the base of the screwdriver slot as previouslydescribed. The structure' and -'operation' ofthis'species is otherwiseidentical with that of'Figskl to 7; This species, though somewhat morefragile than thatpr'eviously described, has the advantage of providingequal torque in either direction.

Figs. 10 to 14 illustrate a further modification of the hits as appliedto'Phillips screws. Therein each of bits 52 and 54 is foldedlongitudinally along its midline so that the lateral edge portions 56thereof, as best shown in Fig. 13, are'inclined substantially at rightangles'to each other, and are inclined outwardly from the midplane ofthe device substantially at forty-five degrees. The ends of the bits aretapered, as indicated at 58. The edge portions 56 ofeach bit are adaptedto be inserted in two adjacent arms of the screw slot 36, and to gripthe side walls of said slot when the bits are expanded by the screwdriver bit.

Fig. 11 shows the special Phillips screw adaptation of the'attachmentmounted on a standard screwdriver shank 4 and operable by the bit 8thereof. Figs. 12 and 14 show the attachment mounted on and operable bya Phillips-type screw driver, audit will be apparent that any of'thespecies shown could be so mounted. The Phillips screw driver includes arod like shank 60 with its lower end portion notched longitudinally atits quadrant points to form a bit 62 which is cruciform incross-section, as shown in Fig. l4."' This bit may be regarded 'as twocrossed wedge-shaped bits disposed at right angles to each other, and isspecially'adapted to fit the slot 36 of a Phillips screw. In the presentapplication, the fulcrum members 3tl carried by the arms 18 and 20 ofthe attachment engage slidably the opposite faces 64 and 66 of one ofthe arms of bit 62, as shown in Fig. 14. Since faces 64 and'66are'relatively inclined in a wedge jshape, they serve to expand thescrew holding bits 52 and- 54, or the bits of any of 'thespecies, aspreviously described. The spaced apart relationship ofthe fulcrummembers 30 associated with each of arms 18 and 20 permits them to bridgeover the ar'm'ofthe cruciform bit 62"whieh is not in actual use.

While the wedge-shaped arms of the Phillips screw driver bit 62 functionin connection with the screw holder attachment in most respectsidentically as does the bit 8 of the standard screw driver, it should benoted that the wedge faces 64 and 66 of a Phillips screw driver bit arecommonly not planar, but are arcuately dished. For this reason,partially, the wedge contacting inner ends of fulcrum members 30 arealso formed arcuately, thereby insuring that they will slide freely onany portion of surfaces 64 and 66. This arcuate formation of the fulcrummembers also provides that. they will ride smoothly on the wedgesurfaces of either type of screw driver despite the rocking movement ofsaid fulcrum members caused by the flexing movements of arms 18 and 20during operation of the device.

Thus it is apparent that a screw holding device having severaladvantages has been produced. It is extremely simple and economical instructure, being formed of a single piece of spring steel stock. It ismountable on and operable by screw drivers of both the standard and thePhillips types, and does not interfere with the ordinary functions ofthe screw drivers. It will function efficiently to hold screws havingthe standard screw driver slot or the cruciform Phillips slot, eventhough theslots vary substantially in width, or are worn or battered.Within limitations inherent in the split-bit type of screw holder, it isquite sturdy and capable of delivering substantial torque. The screwholding bits are protected from damage due to overloading.

Although we have shown and described certain specific embodiments of ourinvention, it is apparent that many minor changes of structure andoperation could be made without departing from the spirit of theinvention as defined by the scope of the appended claims.

What we claim as new and desire to protect by Letters Patent is:

1. A screw holding attachment for a screw driver having a rod-like shankand a wedge-shaped bit at the end of said shank, said attachmentcomprising a member adapted to be mounted on said'shank for frictionalsliding movement therealong, a pair of resilient arms connected at oneend to said sliding member and extending longitudinally of said shank ondiametrically opposite sides thereof, the free end portion of each ofsaid arms being formed to present a longitudinally extending bit, saidbits being adapted by the movement of said sliding member on said shankto be retracted behind or extended for wardly from the end of screwdriver bit, said bits when extended being normally disposed in closejuxtaposition so as to be insertable simultaneously in the screw driverslot of a screw, and a fulcrum member carried by each of said armsadjacent the free end thereof, said fulcrum members extending inwardlyfrom said arms to bear slidably at all times against the respectivewedge faces of said screw driver bit, whereby as said screw driver bitis advanced between said fulcrum members, said bits on said arms will bemoved transversely in opposite directions to engage the side walls ofsaid screw slot, the fulcrum member associated with each of theresilient arms comprising a pair of ears integral with said arm anddisposed respectively at the extreme opposite lateral edges'of said armwhereby to impart a maximum rotational torque to said arm and whereby toprovide a lateral spacing between said ears.

2. The structure as recited in claim 1 wherein the free end portions ofthe bits carried by the arms are tapered for insertion in screw slotshaving inclined walls.

3. The structure as recited in claim 1 wherein the bits carried by thearms are formed of flat stock of equal and coextensive width, the'innerfaces of said bits normally being urged together by the resilience ofsaid arms, and the outer surface of each of said bits being outwardlyinclined in the direction of expanding movement of said bit.

4. The structure as recited in claim 1 wherein the bit carried by eachof said arms is angular in cross-section, the edge portions thereofbeing disposed substantially at right angles to each other and inclinedequally with respect to a central plane passing between said bits.

References Cited in the file of this patent UNITED STATES PATENTS925,115 Loewenberg June 15, 1909 1,178,141 Eckman Apr. 4, 1916 1,392,796Reinhalter Oct. 4, 1921 1,394,438 Mills Oct. 18, 1921 1,742,278 ReidJan. 7, 1930 1,945,829 Sofield Feb. 6, 1934 2,313,710 Gemmell Mar. 9,1943 2,625,971 Bier Jan. 20, 1953

